Updating Travis CI file to setup the test environment correctly

.travis.yml

 language: ruby
 cache: bundler
 
+env:
+  global:
+    - LOCAL_DOMAIN=example.com
+    - LOCAL_HTTPS=false
+
+addons:
+  postgresql: 9.4
+
 rvm:
   - 2.2.4
 
+services:
+  - redis-server
+
 bundler_args: --without development --retry=3 --jobs=3
 
+before_script:
+  - bundle exec rake db:create db:migrate
+
 script: bundle exec rspec